Panic gripped the young mother when she found her 15-month-old daughter holding a half-empty bottle of baby aspiran.Frantically she tried to determine how many pills the child had swallowed. All the while, her mind wrestled with the vision of a comatose child -- the victim of an accidential posioning.

Finally, the mother determined that the child, who weighted 23 pounds, had ingested about 11 pills -- not enought to poison her or require that her stomach be emptied, said Dr. Tolby Litovitz of the National Capital Posion Center at Georgetown University Hospital.

The center, one of 52 in the National Posion Center Network, opened this fall and will serve as headquarters to aid poison victims in the metropolitan area. The center is in three rooms adjacent to the hospital's emergency room. a

Litovitz advises parents to memorize the telephone number of the center -- 625-3333 -- and to keep on hand a bottle of syrup of ipecac, a vomit- inducing agent sold without prescription for about $1.

Litovitz suggests that parents call the center immediately if a poisoning is suspected rather than follow guidelines for emergency treatment suggested in poison-prevention pamphlets distributed by some area stores.

"I'm not saying they are wrong, but I can't say they are right," she said.

Never administer ipecac, the vomit inducing agent, except on the advice of medical personnel, she added, because it is not advisable in some poisonings.

"Alway call the poison center first," she repeated.

Toxic substances always should be kept in their original containers and out of chilren's reach. Dangerous plants -- in and out of doors -- should be labeled and also kept out of reach.

One way to label toxic products is to use the green Mr. Yuk stickers, which are available by calling the Georgetown center. Even young children can be taught to keep hands off Mr. Yuk containers, Litovitz said.

Other prevention measures include protective capping on medicine bottles. In addition, Litovitz said, do not mask poisonous substances, such as lacing boric acid with sugar to attract cockroaches.

"It will not kill the bugs," she said, "but a teaspoon of boric acid can kill a child."

At the posion center, phones are answered around the clock by nurses with toxicology training. Litovitz, a physician who specializes in emergency medicine, is available to handle difficult cases, and a small army of nationally recognized poison sepcialists is accessbile by telephone day and night.

It is 5 p.m. The poison center's six telephone lines ring in succession.

Nurse Barbara Fahey is calm and precise as she answers the phone. She quickly takes vital information.

"What has the child swallowed?" she asks. "How old is the child? When did this happen?"

Within 15 minutes she has reassured several frantic mothers whose children have gotten into a variety of undesirable substances.

A 2-year-old has eaten "a couple of mouthfuls" of D-Con rat poison. Another has drunk some Wisk liquid detergent. One has licked Magic Markers, another has eaten kitty litter (neither is poisonous) and a 12-year-old boy has sprayed Pledge furniture polish into his eyes.

In the cases involving the rat poison and detergent, the amounts consumed were negligible and the children did not require emergency treatment. Fahey instructed the mother of the child with furniture polish in his eyes to wash the boy's eyes for 10 minutes. She later made a follow-up call and learned the boy was fine.

Had a child eaten enough of a toxic substance to place him or her in danger, Fahey would have instructed the parent to induce vomiting, take the child to the nearest hospital emergency room or both.

She then would have alerted emergency room personnel.

At Fahey's fingertips is a file of microfiche cards that can be inserted into an electronic viewer to identify a poison by its brand name and its chemcial composition. Each card gives specific symptoms the posion causes and step-by-step treatment.

Known as Poisindex, the file enables Fahey to tell physicians what antidotes to administer.

For 25 years, the area's only poison center was at Children's Hospital National Medical Center. Children's will now provide supportive services to the Georgetown posion center, as will many area hospitals. Numbers Outside Of Washington Area

In Northern Virginia, the numbers for poison control information that appear in the current telephone book are hospital emergency room numbers and should no longer be used.

If you live south of Loudoun or Prince William counties, call the poison control center at the University of Virginia Hospital in Charlottesville at 804-924-5543, or the Central Virginia Poison Control Center in Richmond at 804-786-9123.